In an electronic device such as a radar device or communication equipment, a coaxial connector is widely used as an input/output interface for a high-frequency signal. A strip line including a microstrip line is widely used as means for propagating a high-frequency signal within an electronic device.
As a method of connecting a coaxial connector and a microstrip line, Japanese Utility Model Laying-Open No. 2-36202 describes in FIG. 1 (see PTD 1 below) a configuration in which a connector core of a coaxial connector and a microstrip line are connected by a gold ribbon.
However, considering the deformation caused by a difference in linear expansion during temperature change between a housing to which the coaxial connector is attached and a substrate on which the microstrip line is formed, a gap is provided between the housing and the substrate as shown in FIG. 2 of PTD 1. Thus, there is a concern about leakage of a high-frequency signal (electric wave) through this gap.
As means for solving this problem, a method has been used of directly connecting a central conductor of a coaxial connector and a microstrip line in a closed space, as in FIGS. 1 and 2 of Japanese Patent Laying-Open No. 5-259713 (see PTD 2 below).